Abstract: A variable displacement pump supplies fluid to the single acting draft control cylinder of an agricultural tractor through a valve for controlling flow to and from the draft control cylinder. The valve houses a control rod activated valve spool that when displaced allows fluid to unseat a check valve between the spool valve and the draft control cylinder.Fluid is exhausted from the draft control cylinder when the control rod causes unseating of a main poppet by unseating a pilot valve in the main poppet. Fluid being exhausted from the draft control cylinder then passes through the valve to tank.

Abstract: A simple load sensitive hydraulic system having a variable displacement pump, a priority dependent work circuit, at least one secondary work circuit, priority means preferencing fluid flow to the priority dependent work circuit over the secondary work circuit, flow and pressure compensating means responsive to requirements of either work circuit for controlling displacement of the variable displacement pump and a relief valve which when overridden allows fluid flow to the secondary work circuit.

Abstract: A fluid operated motor amplifies input force and communicates a greater amount of output force to a reaction device. Input effort is directly proportional to the amplified output effort. A power piston residing in a cylinder bore has an input rod, having a spool valve and a reaction piston, laterally movable through a bore in the power piston. Fluid flow is metered to a working chamber by the spool valve in response to the position of the input rod. An output rod moves with the power piston to deliver an amplified force to a linkage.

Abstract: A load sensitive hydraulic system having a variable displacement pump, a priority dependent work circuit, at least one secondary work circuit, priority means preferencing fluid flow to the priority dependent work circuit over the secondary work circuit, flow and pressure compensating means responsive to requirements of either work circuit for controlling displacement of the variable displacement pump and a relief valve, when overriden, allowing fluid flow to the secondary work circuit.